2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
18 #include <linux/sched.h>
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/buffer_head.h>
22 #include <linux/blkdev.h>
23 #include <linux/random.h>
24 #include <linux/iocontext.h>
25 #include <linux/capability.h>
26 #include <asm/div64.h>
29 #include "extent_map.h"
31 #include "transaction.h"
32 #include "print-tree.h"
34 #include "async-thread.h"
36 static int init_first_rw_device(struct btrfs_trans_handle *trans,
37 struct btrfs_root *root,
38 struct btrfs_device *device);
39 static int btrfs_relocate_sys_chunks(struct btrfs_root *root);
41 static DEFINE_MUTEX(uuid_mutex);
42 static LIST_HEAD(fs_uuids);
44 static void lock_chunks(struct btrfs_root *root)
46 mutex_lock(&root->fs_info->chunk_mutex);
49 static void unlock_chunks(struct btrfs_root *root)
51 mutex_unlock(&root->fs_info->chunk_mutex);
54 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
56 struct btrfs_device *device;
57 WARN_ON(fs_devices->opened);
58 while (!list_empty(&fs_devices->devices)) {
59 device = list_entry(fs_devices->devices.next,
60 struct btrfs_device, dev_list);
61 list_del(&device->dev_list);
68 int btrfs_cleanup_fs_uuids(void)
70 struct btrfs_fs_devices *fs_devices;
72 while (!list_empty(&fs_uuids)) {
73 fs_devices = list_entry(fs_uuids.next,
74 struct btrfs_fs_devices, list);
75 list_del(&fs_devices->list);
76 free_fs_devices(fs_devices);
81 static noinline struct btrfs_device *__find_device(struct list_head *head,
84 struct btrfs_device *dev;
86 list_for_each_entry(dev, head, dev_list) {
87 if (dev->devid == devid &&
88 (!uuid || !memcmp(dev->uuid, uuid, BTRFS_UUID_SIZE))) {
95 static noinline struct btrfs_fs_devices *find_fsid(u8 *fsid)
97 struct btrfs_fs_devices *fs_devices;
99 list_for_each_entry(fs_devices, &fs_uuids, list) {
100 if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) == 0)
106 static void requeue_list(struct btrfs_pending_bios *pending_bios,
107 struct bio *head, struct bio *tail)
110 struct bio *old_head;
112 old_head = pending_bios->head;
113 pending_bios->head = head;
114 if (pending_bios->tail)
115 tail->bi_next = old_head;
117 pending_bios->tail = tail;
121 * we try to collect pending bios for a device so we don't get a large
122 * number of procs sending bios down to the same device. This greatly
123 * improves the schedulers ability to collect and merge the bios.
125 * But, it also turns into a long list of bios to process and that is sure
126 * to eventually make the worker thread block. The solution here is to
127 * make some progress and then put this work struct back at the end of
128 * the list if the block device is congested. This way, multiple devices
129 * can make progress from a single worker thread.
131 static noinline int run_scheduled_bios(struct btrfs_device *device)
134 struct backing_dev_info *bdi;
135 struct btrfs_fs_info *fs_info;
136 struct btrfs_pending_bios *pending_bios;
140 unsigned long num_run;
141 unsigned long batch_run = 0;
143 unsigned long last_waited = 0;
145 struct blk_plug plug;
148 * this function runs all the bios we've collected for
149 * a particular device. We don't want to wander off to
150 * another device without first sending all of these down.
151 * So, setup a plug here and finish it off before we return
153 blk_start_plug(&plug);
155 bdi = blk_get_backing_dev_info(device->bdev);
156 fs_info = device->dev_root->fs_info;
157 limit = btrfs_async_submit_limit(fs_info);
158 limit = limit * 2 / 3;
161 spin_lock(&device->io_lock);
166 /* take all the bios off the list at once and process them
167 * later on (without the lock held). But, remember the
168 * tail and other pointers so the bios can be properly reinserted
169 * into the list if we hit congestion
171 if (!force_reg && device->pending_sync_bios.head) {
172 pending_bios = &device->pending_sync_bios;
175 pending_bios = &device->pending_bios;
179 pending = pending_bios->head;
180 tail = pending_bios->tail;
181 WARN_ON(pending && !tail);
184 * if pending was null this time around, no bios need processing
185 * at all and we can stop. Otherwise it'll loop back up again
186 * and do an additional check so no bios are missed.
188 * device->running_pending is used to synchronize with the
191 if (device->pending_sync_bios.head == NULL &&
192 device->pending_bios.head == NULL) {
194 device->running_pending = 0;
197 device->running_pending = 1;
200 pending_bios->head = NULL;
201 pending_bios->tail = NULL;
203 spin_unlock(&device->io_lock);
208 /* we want to work on both lists, but do more bios on the
209 * sync list than the regular list
212 pending_bios != &device->pending_sync_bios &&
213 device->pending_sync_bios.head) ||
214 (num_run > 64 && pending_bios == &device->pending_sync_bios &&
215 device->pending_bios.head)) {
216 spin_lock(&device->io_lock);
217 requeue_list(pending_bios, pending, tail);
222 pending = pending->bi_next;
224 atomic_dec(&fs_info->nr_async_bios);
226 if (atomic_read(&fs_info->nr_async_bios) < limit &&
227 waitqueue_active(&fs_info->async_submit_wait))
228 wake_up(&fs_info->async_submit_wait);
230 BUG_ON(atomic_read(&cur->bi_cnt) == 0);
232 submit_bio(cur->bi_rw, cur);
239 * we made progress, there is more work to do and the bdi
240 * is now congested. Back off and let other work structs
243 if (pending && bdi_write_congested(bdi) && batch_run > 8 &&
244 fs_info->fs_devices->open_devices > 1) {
245 struct io_context *ioc;
247 ioc = current->io_context;
250 * the main goal here is that we don't want to
251 * block if we're going to be able to submit
252 * more requests without blocking.
254 * This code does two great things, it pokes into
255 * the elevator code from a filesystem _and_
256 * it makes assumptions about how batching works.
258 if (ioc && ioc->nr_batch_requests > 0 &&
259 time_before(jiffies, ioc->last_waited + HZ/50UL) &&
261 ioc->last_waited == last_waited)) {
263 * we want to go through our batch of
264 * requests and stop. So, we copy out
265 * the ioc->last_waited time and test
266 * against it before looping
268 last_waited = ioc->last_waited;
273 spin_lock(&device->io_lock);
274 requeue_list(pending_bios, pending, tail);
275 device->running_pending = 1;
277 spin_unlock(&device->io_lock);
278 btrfs_requeue_work(&device->work);
287 spin_lock(&device->io_lock);
288 if (device->pending_bios.head || device->pending_sync_bios.head)
290 spin_unlock(&device->io_lock);
293 blk_finish_plug(&plug);
297 static void pending_bios_fn(struct btrfs_work *work)
299 struct btrfs_device *device;
301 device = container_of(work, struct btrfs_device, work);
302 run_scheduled_bios(device);
305 static noinline int device_list_add(const char *path,
306 struct btrfs_super_block *disk_super,
307 u64 devid, struct btrfs_fs_devices **fs_devices_ret)
309 struct btrfs_device *device;
310 struct btrfs_fs_devices *fs_devices;
311 u64 found_transid = btrfs_super_generation(disk_super);
314 fs_devices = find_fsid(disk_super->fsid);
316 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
319 INIT_LIST_HEAD(&fs_devices->devices);
320 INIT_LIST_HEAD(&fs_devices->alloc_list);
321 list_add(&fs_devices->list, &fs_uuids);
322 memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
323 fs_devices->latest_devid = devid;
324 fs_devices->latest_trans = found_transid;
325 mutex_init(&fs_devices->device_list_mutex);
328 device = __find_device(&fs_devices->devices, devid,
329 disk_super->dev_item.uuid);
332 if (fs_devices->opened)
335 device = kzalloc(sizeof(*device), GFP_NOFS);
337 /* we can safely leave the fs_devices entry around */
340 device->devid = devid;
341 device->work.func = pending_bios_fn;
342 memcpy(device->uuid, disk_super->dev_item.uuid,
344 spin_lock_init(&device->io_lock);
345 device->name = kstrdup(path, GFP_NOFS);
350 INIT_LIST_HEAD(&device->dev_alloc_list);
352 mutex_lock(&fs_devices->device_list_mutex);
353 list_add_rcu(&device->dev_list, &fs_devices->devices);
354 mutex_unlock(&fs_devices->device_list_mutex);
356 device->fs_devices = fs_devices;
357 fs_devices->num_devices++;
358 } else if (!device->name || strcmp(device->name, path)) {
359 name = kstrdup(path, GFP_NOFS);
364 if (device->missing) {
365 fs_devices->missing_devices--;
370 if (found_transid > fs_devices->latest_trans) {
371 fs_devices->latest_devid = devid;
372 fs_devices->latest_trans = found_transid;
374 *fs_devices_ret = fs_devices;
378 static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
380 struct btrfs_fs_devices *fs_devices;
381 struct btrfs_device *device;
382 struct btrfs_device *orig_dev;
384 fs_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
386 return ERR_PTR(-ENOMEM);
388 INIT_LIST_HEAD(&fs_devices->devices);
389 INIT_LIST_HEAD(&fs_devices->alloc_list);
390 INIT_LIST_HEAD(&fs_devices->list);
391 mutex_init(&fs_devices->device_list_mutex);
392 fs_devices->latest_devid = orig->latest_devid;
393 fs_devices->latest_trans = orig->latest_trans;
394 memcpy(fs_devices->fsid, orig->fsid, sizeof(fs_devices->fsid));
396 /* We have held the volume lock, it is safe to get the devices. */
397 list_for_each_entry(orig_dev, &orig->devices, dev_list) {
398 device = kzalloc(sizeof(*device), GFP_NOFS);
402 device->name = kstrdup(orig_dev->name, GFP_NOFS);
408 device->devid = orig_dev->devid;
409 device->work.func = pending_bios_fn;
410 memcpy(device->uuid, orig_dev->uuid, sizeof(device->uuid));
411 spin_lock_init(&device->io_lock);
412 INIT_LIST_HEAD(&device->dev_list);
413 INIT_LIST_HEAD(&device->dev_alloc_list);
415 list_add(&device->dev_list, &fs_devices->devices);
416 device->fs_devices = fs_devices;
417 fs_devices->num_devices++;
421 free_fs_devices(fs_devices);
422 return ERR_PTR(-ENOMEM);
425 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
427 struct btrfs_device *device, *next;
429 mutex_lock(&uuid_mutex);
431 /* This is the initialized path, it is safe to release the devices. */
432 list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
433 if (device->in_fs_metadata)
437 blkdev_put(device->bdev, device->mode);
439 fs_devices->open_devices--;
441 if (device->writeable) {
442 list_del_init(&device->dev_alloc_list);
443 device->writeable = 0;
444 fs_devices->rw_devices--;
446 list_del_init(&device->dev_list);
447 fs_devices->num_devices--;
452 if (fs_devices->seed) {
453 fs_devices = fs_devices->seed;
457 mutex_unlock(&uuid_mutex);
461 static void __free_device(struct work_struct *work)
463 struct btrfs_device *device;
465 device = container_of(work, struct btrfs_device, rcu_work);
468 blkdev_put(device->bdev, device->mode);
474 static void free_device(struct rcu_head *head)
476 struct btrfs_device *device;
478 device = container_of(head, struct btrfs_device, rcu);
480 INIT_WORK(&device->rcu_work, __free_device);
481 schedule_work(&device->rcu_work);
484 static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
486 struct btrfs_device *device;
488 if (--fs_devices->opened > 0)
491 mutex_lock(&fs_devices->device_list_mutex);
492 list_for_each_entry(device, &fs_devices->devices, dev_list) {
493 struct btrfs_device *new_device;
496 fs_devices->open_devices--;
498 if (device->writeable) {
499 list_del_init(&device->dev_alloc_list);
500 fs_devices->rw_devices--;
503 new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
505 memcpy(new_device, device, sizeof(*new_device));
506 new_device->name = kstrdup(device->name, GFP_NOFS);
507 BUG_ON(device->name && !new_device->name);
508 new_device->bdev = NULL;
509 new_device->writeable = 0;
510 new_device->in_fs_metadata = 0;
511 list_replace_rcu(&device->dev_list, &new_device->dev_list);
513 call_rcu(&device->rcu, free_device);
515 mutex_unlock(&fs_devices->device_list_mutex);
517 WARN_ON(fs_devices->open_devices);
518 WARN_ON(fs_devices->rw_devices);
519 fs_devices->opened = 0;
520 fs_devices->seeding = 0;
525 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
527 struct btrfs_fs_devices *seed_devices = NULL;
530 mutex_lock(&uuid_mutex);
531 ret = __btrfs_close_devices(fs_devices);
532 if (!fs_devices->opened) {
533 seed_devices = fs_devices->seed;
534 fs_devices->seed = NULL;
536 mutex_unlock(&uuid_mutex);
538 while (seed_devices) {
539 fs_devices = seed_devices;
540 seed_devices = fs_devices->seed;
541 __btrfs_close_devices(fs_devices);
542 free_fs_devices(fs_devices);
547 static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
548 fmode_t flags, void *holder)
550 struct block_device *bdev;
551 struct list_head *head = &fs_devices->devices;
552 struct btrfs_device *device;
553 struct block_device *latest_bdev = NULL;
554 struct buffer_head *bh;
555 struct btrfs_super_block *disk_super;
556 u64 latest_devid = 0;
557 u64 latest_transid = 0;
564 list_for_each_entry(device, head, dev_list) {
570 bdev = blkdev_get_by_path(device->name, flags, holder);
572 printk(KERN_INFO "open %s failed\n", device->name);
575 set_blocksize(bdev, 4096);
577 bh = btrfs_read_dev_super(bdev);
583 disk_super = (struct btrfs_super_block *)bh->b_data;
584 devid = btrfs_stack_device_id(&disk_super->dev_item);
585 if (devid != device->devid)
588 if (memcmp(device->uuid, disk_super->dev_item.uuid,
592 device->generation = btrfs_super_generation(disk_super);
593 if (!latest_transid || device->generation > latest_transid) {
594 latest_devid = devid;
595 latest_transid = device->generation;
599 if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) {
600 device->writeable = 0;
602 device->writeable = !bdev_read_only(bdev);
607 device->in_fs_metadata = 0;
608 device->mode = flags;
610 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
611 fs_devices->rotating = 1;
613 fs_devices->open_devices++;
614 if (device->writeable) {
615 fs_devices->rw_devices++;
616 list_add(&device->dev_alloc_list,
617 &fs_devices->alloc_list);
625 blkdev_put(bdev, flags);
629 if (fs_devices->open_devices == 0) {
633 fs_devices->seeding = seeding;
634 fs_devices->opened = 1;
635 fs_devices->latest_bdev = latest_bdev;
636 fs_devices->latest_devid = latest_devid;
637 fs_devices->latest_trans = latest_transid;
638 fs_devices->total_rw_bytes = 0;
643 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
644 fmode_t flags, void *holder)
648 mutex_lock(&uuid_mutex);
649 if (fs_devices->opened) {
650 fs_devices->opened++;
653 ret = __btrfs_open_devices(fs_devices, flags, holder);
655 mutex_unlock(&uuid_mutex);
659 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
660 struct btrfs_fs_devices **fs_devices_ret)
662 struct btrfs_super_block *disk_super;
663 struct block_device *bdev;
664 struct buffer_head *bh;
669 mutex_lock(&uuid_mutex);
672 bdev = blkdev_get_by_path(path, flags, holder);
679 ret = set_blocksize(bdev, 4096);
682 bh = btrfs_read_dev_super(bdev);
687 disk_super = (struct btrfs_super_block *)bh->b_data;
688 devid = btrfs_stack_device_id(&disk_super->dev_item);
689 transid = btrfs_super_generation(disk_super);
690 if (disk_super->label[0])
691 printk(KERN_INFO "device label %s ", disk_super->label);
693 /* FIXME, make a readl uuid parser */
694 printk(KERN_INFO "device fsid %llx-%llx ",
695 *(unsigned long long *)disk_super->fsid,
696 *(unsigned long long *)(disk_super->fsid + 8));
698 printk(KERN_CONT "devid %llu transid %llu %s\n",
699 (unsigned long long)devid, (unsigned long long)transid, path);
700 ret = device_list_add(path, disk_super, devid, fs_devices_ret);
704 blkdev_put(bdev, flags);
706 mutex_unlock(&uuid_mutex);
710 /* helper to account the used device space in the range */
711 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
712 u64 end, u64 *length)
714 struct btrfs_key key;
715 struct btrfs_root *root = device->dev_root;
716 struct btrfs_dev_extent *dev_extent;
717 struct btrfs_path *path;
721 struct extent_buffer *l;
725 if (start >= device->total_bytes)
728 path = btrfs_alloc_path();
733 key.objectid = device->devid;
735 key.type = BTRFS_DEV_EXTENT_KEY;
737 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
741 ret = btrfs_previous_item(root, path, key.objectid, key.type);
748 slot = path->slots[0];
749 if (slot >= btrfs_header_nritems(l)) {
750 ret = btrfs_next_leaf(root, path);
758 btrfs_item_key_to_cpu(l, &key, slot);
760 if (key.objectid < device->devid)
763 if (key.objectid > device->devid)
766 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
769 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
770 extent_end = key.offset + btrfs_dev_extent_length(l,
772 if (key.offset <= start && extent_end > end) {
773 *length = end - start + 1;
775 } else if (key.offset <= start && extent_end > start)
776 *length += extent_end - start;
777 else if (key.offset > start && extent_end <= end)
778 *length += extent_end - key.offset;
779 else if (key.offset > start && key.offset <= end) {
780 *length += end - key.offset + 1;
782 } else if (key.offset > end)
790 btrfs_free_path(path);
795 * find_free_dev_extent - find free space in the specified device
796 * @trans: transaction handler
797 * @device: the device which we search the free space in
798 * @num_bytes: the size of the free space that we need
799 * @start: store the start of the free space.
800 * @len: the size of the free space. that we find, or the size of the max
801 * free space if we don't find suitable free space
803 * this uses a pretty simple search, the expectation is that it is
804 * called very infrequently and that a given device has a small number
807 * @start is used to store the start of the free space if we find. But if we
808 * don't find suitable free space, it will be used to store the start position
809 * of the max free space.
811 * @len is used to store the size of the free space that we find.
812 * But if we don't find suitable free space, it is used to store the size of
813 * the max free space.
815 int find_free_dev_extent(struct btrfs_trans_handle *trans,
816 struct btrfs_device *device, u64 num_bytes,
817 u64 *start, u64 *len)
819 struct btrfs_key key;
820 struct btrfs_root *root = device->dev_root;
821 struct btrfs_dev_extent *dev_extent;
822 struct btrfs_path *path;
828 u64 search_end = device->total_bytes;
831 struct extent_buffer *l;
833 /* FIXME use last free of some kind */
835 /* we don't want to overwrite the superblock on the drive,
836 * so we make sure to start at an offset of at least 1MB
838 search_start = max(root->fs_info->alloc_start, 1024ull * 1024);
840 max_hole_start = search_start;
843 if (search_start >= search_end) {
848 path = btrfs_alloc_path();
855 key.objectid = device->devid;
856 key.offset = search_start;
857 key.type = BTRFS_DEV_EXTENT_KEY;
859 ret = btrfs_search_slot(trans, root, &key, path, 0, 0);
863 ret = btrfs_previous_item(root, path, key.objectid, key.type);
870 slot = path->slots[0];
871 if (slot >= btrfs_header_nritems(l)) {
872 ret = btrfs_next_leaf(root, path);
880 btrfs_item_key_to_cpu(l, &key, slot);
882 if (key.objectid < device->devid)
885 if (key.objectid > device->devid)
888 if (btrfs_key_type(&key) != BTRFS_DEV_EXTENT_KEY)
891 if (key.offset > search_start) {
892 hole_size = key.offset - search_start;
894 if (hole_size > max_hole_size) {
895 max_hole_start = search_start;
896 max_hole_size = hole_size;
900 * If this free space is greater than which we need,
901 * it must be the max free space that we have found
902 * until now, so max_hole_start must point to the start
903 * of this free space and the length of this free space
904 * is stored in max_hole_size. Thus, we return
905 * max_hole_start and max_hole_size and go back to the
908 if (hole_size >= num_bytes) {
914 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
915 extent_end = key.offset + btrfs_dev_extent_length(l,
917 if (extent_end > search_start)
918 search_start = extent_end;
924 hole_size = search_end- search_start;
925 if (hole_size > max_hole_size) {
926 max_hole_start = search_start;
927 max_hole_size = hole_size;
931 if (hole_size < num_bytes)
937 btrfs_free_path(path);
939 *start = max_hole_start;
941 *len = max_hole_size;
945 static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
946 struct btrfs_device *device,
950 struct btrfs_path *path;
951 struct btrfs_root *root = device->dev_root;
952 struct btrfs_key key;
953 struct btrfs_key found_key;
954 struct extent_buffer *leaf = NULL;
955 struct btrfs_dev_extent *extent = NULL;
957 path = btrfs_alloc_path();
961 key.objectid = device->devid;
963 key.type = BTRFS_DEV_EXTENT_KEY;
965 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
967 ret = btrfs_previous_item(root, path, key.objectid,
968 BTRFS_DEV_EXTENT_KEY);
971 leaf = path->nodes[0];
972 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
973 extent = btrfs_item_ptr(leaf, path->slots[0],
974 struct btrfs_dev_extent);
975 BUG_ON(found_key.offset > start || found_key.offset +
976 btrfs_dev_extent_length(leaf, extent) < start);
977 } else if (ret == 0) {
978 leaf = path->nodes[0];
979 extent = btrfs_item_ptr(leaf, path->slots[0],
980 struct btrfs_dev_extent);
984 if (device->bytes_used > 0)
985 device->bytes_used -= btrfs_dev_extent_length(leaf, extent);
986 ret = btrfs_del_item(trans, root, path);
989 btrfs_free_path(path);
993 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
994 struct btrfs_device *device,
995 u64 chunk_tree, u64 chunk_objectid,
996 u64 chunk_offset, u64 start, u64 num_bytes)
999 struct btrfs_path *path;
1000 struct btrfs_root *root = device->dev_root;
1001 struct btrfs_dev_extent *extent;
1002 struct extent_buffer *leaf;
1003 struct btrfs_key key;
1005 WARN_ON(!device->in_fs_metadata);
1006 path = btrfs_alloc_path();
1010 key.objectid = device->devid;
1012 key.type = BTRFS_DEV_EXTENT_KEY;
1013 ret = btrfs_insert_empty_item(trans, root, path, &key,
1017 leaf = path->nodes[0];
1018 extent = btrfs_item_ptr(leaf, path->slots[0],
1019 struct btrfs_dev_extent);
1020 btrfs_set_dev_extent_chunk_tree(leaf, extent, chunk_tree);
1021 btrfs_set_dev_extent_chunk_objectid(leaf, extent, chunk_objectid);
1022 btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
1024 write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
1025 (unsigned long)btrfs_dev_extent_chunk_tree_uuid(extent),
1028 btrfs_set_dev_extent_length(leaf, extent, num_bytes);
1029 btrfs_mark_buffer_dirty(leaf);
1030 btrfs_free_path(path);
1034 static noinline int find_next_chunk(struct btrfs_root *root,
1035 u64 objectid, u64 *offset)
1037 struct btrfs_path *path;
1039 struct btrfs_key key;
1040 struct btrfs_chunk *chunk;
1041 struct btrfs_key found_key;
1043 path = btrfs_alloc_path();
1046 key.objectid = objectid;
1047 key.offset = (u64)-1;
1048 key.type = BTRFS_CHUNK_ITEM_KEY;
1050 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1056 ret = btrfs_previous_item(root, path, 0, BTRFS_CHUNK_ITEM_KEY);
1060 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1062 if (found_key.objectid != objectid)
1065 chunk = btrfs_item_ptr(path->nodes[0], path->slots[0],
1066 struct btrfs_chunk);
1067 *offset = found_key.offset +
1068 btrfs_chunk_length(path->nodes[0], chunk);
1073 btrfs_free_path(path);
1077 static noinline int find_next_devid(struct btrfs_root *root, u64 *objectid)
1080 struct btrfs_key key;
1081 struct btrfs_key found_key;
1082 struct btrfs_path *path;
1084 root = root->fs_info->chunk_root;
1086 path = btrfs_alloc_path();
1090 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1091 key.type = BTRFS_DEV_ITEM_KEY;
1092 key.offset = (u64)-1;
1094 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1100 ret = btrfs_previous_item(root, path, BTRFS_DEV_ITEMS_OBJECTID,
1101 BTRFS_DEV_ITEM_KEY);
1105 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1107 *objectid = found_key.offset + 1;
1111 btrfs_free_path(path);
1116 * the device information is stored in the chunk root
1117 * the btrfs_device struct should be fully filled in
1119 int btrfs_add_device(struct btrfs_trans_handle *trans,
1120 struct btrfs_root *root,
1121 struct btrfs_device *device)
1124 struct btrfs_path *path;
1125 struct btrfs_dev_item *dev_item;
1126 struct extent_buffer *leaf;
1127 struct btrfs_key key;
1130 root = root->fs_info->chunk_root;
1132 path = btrfs_alloc_path();
1136 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1137 key.type = BTRFS_DEV_ITEM_KEY;
1138 key.offset = device->devid;
1140 ret = btrfs_insert_empty_item(trans, root, path, &key,
1145 leaf = path->nodes[0];
1146 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1148 btrfs_set_device_id(leaf, dev_item, device->devid);
1149 btrfs_set_device_generation(leaf, dev_item, 0);
1150 btrfs_set_device_type(leaf, dev_item, device->type);
1151 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1152 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1153 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1154 btrfs_set_device_total_bytes(leaf, dev_item, device->total_bytes);
1155 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1156 btrfs_set_device_group(leaf, dev_item, 0);
1157 btrfs_set_device_seek_speed(leaf, dev_item, 0);
1158 btrfs_set_device_bandwidth(leaf, dev_item, 0);
1159 btrfs_set_device_start_offset(leaf, dev_item, 0);
1161 ptr = (unsigned long)btrfs_device_uuid(dev_item);
1162 write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
1163 ptr = (unsigned long)btrfs_device_fsid(dev_item);
1164 write_extent_buffer(leaf, root->fs_info->fsid, ptr, BTRFS_UUID_SIZE);
1165 btrfs_mark_buffer_dirty(leaf);
1169 btrfs_free_path(path);
1173 static int btrfs_rm_dev_item(struct btrfs_root *root,
1174 struct btrfs_device *device)
1177 struct btrfs_path *path;
1178 struct btrfs_key key;
1179 struct btrfs_trans_handle *trans;
1181 root = root->fs_info->chunk_root;
1183 path = btrfs_alloc_path();
1187 trans = btrfs_start_transaction(root, 0);
1188 if (IS_ERR(trans)) {
1189 btrfs_free_path(path);
1190 return PTR_ERR(trans);
1192 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1193 key.type = BTRFS_DEV_ITEM_KEY;
1194 key.offset = device->devid;
1197 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1206 ret = btrfs_del_item(trans, root, path);
1210 btrfs_free_path(path);
1211 unlock_chunks(root);
1212 btrfs_commit_transaction(trans, root);
1216 int btrfs_rm_device(struct btrfs_root *root, char *device_path)
1218 struct btrfs_device *device;
1219 struct btrfs_device *next_device;
1220 struct block_device *bdev;
1221 struct buffer_head *bh = NULL;
1222 struct btrfs_super_block *disk_super;
1223 struct btrfs_fs_devices *cur_devices;
1229 bool clear_super = false;
1231 mutex_lock(&uuid_mutex);
1232 mutex_lock(&root->fs_info->volume_mutex);
1234 all_avail = root->fs_info->avail_data_alloc_bits |
1235 root->fs_info->avail_system_alloc_bits |
1236 root->fs_info->avail_metadata_alloc_bits;
1238 if ((all_avail & BTRFS_BLOCK_GROUP_RAID10) &&
1239 root->fs_info->fs_devices->num_devices <= 4) {
1240 printk(KERN_ERR "btrfs: unable to go below four devices "
1246 if ((all_avail & BTRFS_BLOCK_GROUP_RAID1) &&
1247 root->fs_info->fs_devices->num_devices <= 2) {
1248 printk(KERN_ERR "btrfs: unable to go below two "
1249 "devices on raid1\n");
1254 if (strcmp(device_path, "missing") == 0) {
1255 struct list_head *devices;
1256 struct btrfs_device *tmp;
1259 devices = &root->fs_info->fs_devices->devices;
1261 * It is safe to read the devices since the volume_mutex
1264 list_for_each_entry(tmp, devices, dev_list) {
1265 if (tmp->in_fs_metadata && !tmp->bdev) {
1274 printk(KERN_ERR "btrfs: no missing devices found to "
1279 bdev = blkdev_get_by_path(device_path, FMODE_READ | FMODE_EXCL,
1280 root->fs_info->bdev_holder);
1282 ret = PTR_ERR(bdev);
1286 set_blocksize(bdev, 4096);
1287 bh = btrfs_read_dev_super(bdev);
1292 disk_super = (struct btrfs_super_block *)bh->b_data;
1293 devid = btrfs_stack_device_id(&disk_super->dev_item);
1294 dev_uuid = disk_super->dev_item.uuid;
1295 device = btrfs_find_device(root, devid, dev_uuid,
1303 if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
1304 printk(KERN_ERR "btrfs: unable to remove the only writeable "
1310 if (device->writeable) {
1312 list_del_init(&device->dev_alloc_list);
1313 unlock_chunks(root);
1314 root->fs_info->fs_devices->rw_devices--;
1318 ret = btrfs_shrink_device(device, 0);
1322 ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
1326 device->in_fs_metadata = 0;
1327 btrfs_scrub_cancel_dev(root, device);
1330 * the device list mutex makes sure that we don't change
1331 * the device list while someone else is writing out all
1332 * the device supers.
1335 cur_devices = device->fs_devices;
1336 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1337 list_del_rcu(&device->dev_list);
1339 device->fs_devices->num_devices--;
1341 if (device->missing)
1342 root->fs_info->fs_devices->missing_devices--;
1344 next_device = list_entry(root->fs_info->fs_devices->devices.next,
1345 struct btrfs_device, dev_list);
1346 if (device->bdev == root->fs_info->sb->s_bdev)
1347 root->fs_info->sb->s_bdev = next_device->bdev;
1348 if (device->bdev == root->fs_info->fs_devices->latest_bdev)
1349 root->fs_info->fs_devices->latest_bdev = next_device->bdev;
1352 device->fs_devices->open_devices--;
1354 call_rcu(&device->rcu, free_device);
1355 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1357 num_devices = btrfs_super_num_devices(&root->fs_info->super_copy) - 1;
1358 btrfs_set_super_num_devices(&root->fs_info->super_copy, num_devices);
1360 if (cur_devices->open_devices == 0) {
1361 struct btrfs_fs_devices *fs_devices;
1362 fs_devices = root->fs_info->fs_devices;
1363 while (fs_devices) {
1364 if (fs_devices->seed == cur_devices)
1366 fs_devices = fs_devices->seed;
1368 fs_devices->seed = cur_devices->seed;
1369 cur_devices->seed = NULL;
1371 __btrfs_close_devices(cur_devices);
1372 unlock_chunks(root);
1373 free_fs_devices(cur_devices);
1377 * at this point, the device is zero sized. We want to
1378 * remove it from the devices list and zero out the old super
1381 /* make sure this device isn't detected as part of
1384 memset(&disk_super->magic, 0, sizeof(disk_super->magic));
1385 set_buffer_dirty(bh);
1386 sync_dirty_buffer(bh);
1395 blkdev_put(bdev, FMODE_READ | FMODE_EXCL);
1397 mutex_unlock(&root->fs_info->volume_mutex);
1398 mutex_unlock(&uuid_mutex);
1401 if (device->writeable) {
1403 list_add(&device->dev_alloc_list,
1404 &root->fs_info->fs_devices->alloc_list);
1405 unlock_chunks(root);
1406 root->fs_info->fs_devices->rw_devices++;
1412 * does all the dirty work required for changing file system's UUID.
1414 static int btrfs_prepare_sprout(struct btrfs_trans_handle *trans,
1415 struct btrfs_root *root)
1417 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
1418 struct btrfs_fs_devices *old_devices;
1419 struct btrfs_fs_devices *seed_devices;
1420 struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1421 struct btrfs_device *device;
1424 BUG_ON(!mutex_is_locked(&uuid_mutex));
1425 if (!fs_devices->seeding)
1428 seed_devices = kzalloc(sizeof(*fs_devices), GFP_NOFS);
1432 old_devices = clone_fs_devices(fs_devices);
1433 if (IS_ERR(old_devices)) {
1434 kfree(seed_devices);
1435 return PTR_ERR(old_devices);
1438 list_add(&old_devices->list, &fs_uuids);
1440 memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
1441 seed_devices->opened = 1;
1442 INIT_LIST_HEAD(&seed_devices->devices);
1443 INIT_LIST_HEAD(&seed_devices->alloc_list);
1444 mutex_init(&seed_devices->device_list_mutex);
1446 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1447 list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices,
1449 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1451 list_splice_init(&fs_devices->alloc_list, &seed_devices->alloc_list);
1452 list_for_each_entry(device, &seed_devices->devices, dev_list) {
1453 device->fs_devices = seed_devices;
1456 fs_devices->seeding = 0;
1457 fs_devices->num_devices = 0;
1458 fs_devices->open_devices = 0;
1459 fs_devices->seed = seed_devices;
1461 generate_random_uuid(fs_devices->fsid);
1462 memcpy(root->fs_info->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1463 memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE);
1464 super_flags = btrfs_super_flags(disk_super) &
1465 ~BTRFS_SUPER_FLAG_SEEDING;
1466 btrfs_set_super_flags(disk_super, super_flags);
1472 * strore the expected generation for seed devices in device items.
1474 static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
1475 struct btrfs_root *root)
1477 struct btrfs_path *path;
1478 struct extent_buffer *leaf;
1479 struct btrfs_dev_item *dev_item;
1480 struct btrfs_device *device;
1481 struct btrfs_key key;
1482 u8 fs_uuid[BTRFS_UUID_SIZE];
1483 u8 dev_uuid[BTRFS_UUID_SIZE];
1487 path = btrfs_alloc_path();
1491 root = root->fs_info->chunk_root;
1492 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1494 key.type = BTRFS_DEV_ITEM_KEY;
1497 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1501 leaf = path->nodes[0];
1503 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1504 ret = btrfs_next_leaf(root, path);
1509 leaf = path->nodes[0];
1510 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1511 btrfs_release_path(path);
1515 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1516 if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID ||
1517 key.type != BTRFS_DEV_ITEM_KEY)
1520 dev_item = btrfs_item_ptr(leaf, path->slots[0],
1521 struct btrfs_dev_item);
1522 devid = btrfs_device_id(leaf, dev_item);
1523 read_extent_buffer(leaf, dev_uuid,
1524 (unsigned long)btrfs_device_uuid(dev_item),
1526 read_extent_buffer(leaf, fs_uuid,
1527 (unsigned long)btrfs_device_fsid(dev_item),
1529 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
1532 if (device->fs_devices->seeding) {
1533 btrfs_set_device_generation(leaf, dev_item,
1534 device->generation);
1535 btrfs_mark_buffer_dirty(leaf);
1543 btrfs_free_path(path);
1547 int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
1549 struct btrfs_trans_handle *trans;
1550 struct btrfs_device *device;
1551 struct block_device *bdev;
1552 struct list_head *devices;
1553 struct super_block *sb = root->fs_info->sb;
1555 int seeding_dev = 0;
1558 if ((sb->s_flags & MS_RDONLY) && !root->fs_info->fs_devices->seeding)
1561 bdev = blkdev_get_by_path(device_path, FMODE_EXCL,
1562 root->fs_info->bdev_holder);
1564 return PTR_ERR(bdev);
1566 if (root->fs_info->fs_devices->seeding) {
1568 down_write(&sb->s_umount);
1569 mutex_lock(&uuid_mutex);
1572 filemap_write_and_wait(bdev->bd_inode->i_mapping);
1573 mutex_lock(&root->fs_info->volume_mutex);
1575 devices = &root->fs_info->fs_devices->devices;
1577 * we have the volume lock, so we don't need the extra
1578 * device list mutex while reading the list here.
1580 list_for_each_entry(device, devices, dev_list) {
1581 if (device->bdev == bdev) {
1587 device = kzalloc(sizeof(*device), GFP_NOFS);
1589 /* we can safely leave the fs_devices entry around */
1594 device->name = kstrdup(device_path, GFP_NOFS);
1595 if (!device->name) {
1601 ret = find_next_devid(root, &device->devid);
1603 kfree(device->name);
1608 trans = btrfs_start_transaction(root, 0);
1609 if (IS_ERR(trans)) {
1610 kfree(device->name);
1612 ret = PTR_ERR(trans);
1618 device->writeable = 1;
1619 device->work.func = pending_bios_fn;
1620 generate_random_uuid(device->uuid);
1621 spin_lock_init(&device->io_lock);
1622 device->generation = trans->transid;
1623 device->io_width = root->sectorsize;
1624 device->io_align = root->sectorsize;
1625 device->sector_size = root->sectorsize;
1626 device->total_bytes = i_size_read(bdev->bd_inode);
1627 device->disk_total_bytes = device->total_bytes;
1628 device->dev_root = root->fs_info->dev_root;
1629 device->bdev = bdev;
1630 device->in_fs_metadata = 1;
1631 device->mode = FMODE_EXCL;
1632 set_blocksize(device->bdev, 4096);
1635 sb->s_flags &= ~MS_RDONLY;
1636 ret = btrfs_prepare_sprout(trans, root);
1640 device->fs_devices = root->fs_info->fs_devices;
1643 * we don't want write_supers to jump in here with our device
1646 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
1647 list_add_rcu(&device->dev_list, &root->fs_info->fs_devices->devices);
1648 list_add(&device->dev_alloc_list,
1649 &root->fs_info->fs_devices->alloc_list);
1650 root->fs_info->fs_devices->num_devices++;
1651 root->fs_info->fs_devices->open_devices++;
1652 root->fs_info->fs_devices->rw_devices++;
1653 root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
1655 if (!blk_queue_nonrot(bdev_get_queue(bdev)))
1656 root->fs_info->fs_devices->rotating = 1;
1658 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
1659 btrfs_set_super_total_bytes(&root->fs_info->super_copy,
1660 total_bytes + device->total_bytes);
1662 total_bytes = btrfs_super_num_devices(&root->fs_info->super_copy);
1663 btrfs_set_super_num_devices(&root->fs_info->super_copy,
1665 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
1668 ret = init_first_rw_device(trans, root, device);
1670 ret = btrfs_finish_sprout(trans, root);
1673 ret = btrfs_add_device(trans, root, device);
1677 * we've got more storage, clear any full flags on the space
1680 btrfs_clear_space_info_full(root->fs_info);
1682 unlock_chunks(root);
1683 btrfs_commit_transaction(trans, root);
1686 mutex_unlock(&uuid_mutex);
1687 up_write(&sb->s_umount);
1689 ret = btrfs_relocate_sys_chunks(root);
1693 mutex_unlock(&root->fs_info->volume_mutex);
1696 blkdev_put(bdev, FMODE_EXCL);
1698 mutex_unlock(&uuid_mutex);
1699 up_write(&sb->s_umount);
1704 static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
1705 struct btrfs_device *device)
1708 struct btrfs_path *path;
1709 struct btrfs_root *root;
1710 struct btrfs_dev_item *dev_item;
1711 struct extent_buffer *leaf;
1712 struct btrfs_key key;
1714 root = device->dev_root->fs_info->chunk_root;
1716 path = btrfs_alloc_path();
1720 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
1721 key.type = BTRFS_DEV_ITEM_KEY;
1722 key.offset = device->devid;
1724 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1733 leaf = path->nodes[0];
1734 dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item);
1736 btrfs_set_device_id(leaf, dev_item, device->devid);
1737 btrfs_set_device_type(leaf, dev_item, device->type);
1738 btrfs_set_device_io_align(leaf, dev_item, device->io_align);
1739 btrfs_set_device_io_width(leaf, dev_item, device->io_width);
1740 btrfs_set_device_sector_size(leaf, dev_item, device->sector_size);
1741 btrfs_set_device_total_bytes(leaf, dev_item, device->disk_total_bytes);
1742 btrfs_set_device_bytes_used(leaf, dev_item, device->bytes_used);
1743 btrfs_mark_buffer_dirty(leaf);
1746 btrfs_free_path(path);
1750 static int __btrfs_grow_device(struct btrfs_trans_handle *trans,
1751 struct btrfs_device *device, u64 new_size)
1753 struct btrfs_super_block *super_copy =
1754 &device->dev_root->fs_info->super_copy;
1755 u64 old_total = btrfs_super_total_bytes(super_copy);
1756 u64 diff = new_size - device->total_bytes;
1758 if (!device->writeable)
1760 if (new_size <= device->total_bytes)
1763 btrfs_set_super_total_bytes(super_copy, old_total + diff);
1764 device->fs_devices->total_rw_bytes += diff;
1766 device->total_bytes = new_size;
1767 device->disk_total_bytes = new_size;
1768 btrfs_clear_space_info_full(device->dev_root->fs_info);
1770 return btrfs_update_device(trans, device);
1773 int btrfs_grow_device(struct btrfs_trans_handle *trans,
1774 struct btrfs_device *device, u64 new_size)
1777 lock_chunks(device->dev_root);
1778 ret = __btrfs_grow_device(trans, device, new_size);
1779 unlock_chunks(device->dev_root);
1783 static int btrfs_free_chunk(struct btrfs_trans_handle *trans,
1784 struct btrfs_root *root,
1785 u64 chunk_tree, u64 chunk_objectid,
1789 struct btrfs_path *path;
1790 struct btrfs_key key;
1792 root = root->fs_info->chunk_root;
1793 path = btrfs_alloc_path();
1797 key.objectid = chunk_objectid;
1798 key.offset = chunk_offset;
1799 key.type = BTRFS_CHUNK_ITEM_KEY;
1801 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1804 ret = btrfs_del_item(trans, root, path);
1806 btrfs_free_path(path);
1810 static int btrfs_del_sys_chunk(struct btrfs_root *root, u64 chunk_objectid, u64
1813 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
1814 struct btrfs_disk_key *disk_key;
1815 struct btrfs_chunk *chunk;
1822 struct btrfs_key key;
1824 array_size = btrfs_super_sys_array_size(super_copy);
1826 ptr = super_copy->sys_chunk_array;
1829 while (cur < array_size) {
1830 disk_key = (struct btrfs_disk_key *)ptr;
1831 btrfs_disk_key_to_cpu(&key, disk_key);
1833 len = sizeof(*disk_key);
1835 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
1836 chunk = (struct btrfs_chunk *)(ptr + len);
1837 num_stripes = btrfs_stack_chunk_num_stripes(chunk);
1838 len += btrfs_chunk_item_size(num_stripes);
1843 if (key.objectid == chunk_objectid &&
1844 key.offset == chunk_offset) {
1845 memmove(ptr, ptr + len, array_size - (cur + len));
1847 btrfs_set_super_sys_array_size(super_copy, array_size);
1856 static int btrfs_relocate_chunk(struct btrfs_root *root,
1857 u64 chunk_tree, u64 chunk_objectid,
1860 struct extent_map_tree *em_tree;
1861 struct btrfs_root *extent_root;
1862 struct btrfs_trans_handle *trans;
1863 struct extent_map *em;
1864 struct map_lookup *map;
1868 root = root->fs_info->chunk_root;
1869 extent_root = root->fs_info->extent_root;
1870 em_tree = &root->fs_info->mapping_tree.map_tree;
1872 ret = btrfs_can_relocate(extent_root, chunk_offset);
1876 /* step one, relocate all the extents inside this chunk */
1877 ret = btrfs_relocate_block_group(extent_root, chunk_offset);
1881 trans = btrfs_start_transaction(root, 0);
1882 BUG_ON(IS_ERR(trans));
1887 * step two, delete the device extents and the
1888 * chunk tree entries
1890 read_lock(&em_tree->lock);
1891 em = lookup_extent_mapping(em_tree, chunk_offset, 1);
1892 read_unlock(&em_tree->lock);
1894 BUG_ON(em->start > chunk_offset ||
1895 em->start + em->len < chunk_offset);
1896 map = (struct map_lookup *)em->bdev;
1898 for (i = 0; i < map->num_stripes; i++) {
1899 ret = btrfs_free_dev_extent(trans, map->stripes[i].dev,
1900 map->stripes[i].physical);
1903 if (map->stripes[i].dev) {
1904 ret = btrfs_update_device(trans, map->stripes[i].dev);
1908 ret = btrfs_free_chunk(trans, root, chunk_tree, chunk_objectid,
1913 trace_btrfs_chunk_free(root, map, chunk_offset, em->len);
1915 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
1916 ret = btrfs_del_sys_chunk(root, chunk_objectid, chunk_offset);
1920 ret = btrfs_remove_block_group(trans, extent_root, chunk_offset);
1923 write_lock(&em_tree->lock);
1924 remove_extent_mapping(em_tree, em);
1925 write_unlock(&em_tree->lock);
1930 /* once for the tree */
1931 free_extent_map(em);
1933 free_extent_map(em);
1935 unlock_chunks(root);
1936 btrfs_end_transaction(trans, root);
1940 static int btrfs_relocate_sys_chunks(struct btrfs_root *root)
1942 struct btrfs_root *chunk_root = root->fs_info->chunk_root;
1943 struct btrfs_path *path;
1944 struct extent_buffer *leaf;
1945 struct btrfs_chunk *chunk;
1946 struct btrfs_key key;
1947 struct btrfs_key found_key;
1948 u64 chunk_tree = chunk_root->root_key.objectid;
1950 bool retried = false;
1954 path = btrfs_alloc_path();
1959 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
1960 key.offset = (u64)-1;
1961 key.type = BTRFS_CHUNK_ITEM_KEY;
1964 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
1969 ret = btrfs_previous_item(chunk_root, path, key.objectid,
1976 leaf = path->nodes[0];
1977 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1979 chunk = btrfs_item_ptr(leaf, path->slots[0],
1980 struct btrfs_chunk);
1981 chunk_type = btrfs_chunk_type(leaf, chunk);
1982 btrfs_release_path(path);
1984 if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) {
1985 ret = btrfs_relocate_chunk(chunk_root, chunk_tree,
1994 if (found_key.offset == 0)
1996 key.offset = found_key.offset - 1;
1999 if (failed && !retried) {
2003 } else if (failed && retried) {
2008 btrfs_free_path(path);
2012 static u64 div_factor(u64 num, int factor)
2021 int btrfs_balance(struct btrfs_root *dev_root)
2024 struct list_head *devices = &dev_root->fs_info->fs_devices->devices;
2025 struct btrfs_device *device;
2028 struct btrfs_path *path;
2029 struct btrfs_key key;
2030 struct btrfs_root *chunk_root = dev_root->fs_info->chunk_root;
2031 struct btrfs_trans_handle *trans;
2032 struct btrfs_key found_key;
2034 if (dev_root->fs_info->sb->s_flags & MS_RDONLY)
2037 if (!capable(CAP_SYS_ADMIN))
2040 mutex_lock(&dev_root->fs_info->volume_mutex);
2041 dev_root = dev_root->fs_info->dev_root;
2043 /* step one make some room on all the devices */
2044 list_for_each_entry(device, devices, dev_list) {
2045 old_size = device->total_bytes;
2046 size_to_free = div_factor(old_size, 1);
2047 size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
2048 if (!device->writeable ||
2049 device->total_bytes - device->bytes_used > size_to_free)
2052 ret = btrfs_shrink_device(device, old_size - size_to_free);
2057 trans = btrfs_start_transaction(dev_root, 0);
2058 BUG_ON(IS_ERR(trans));
2060 ret = btrfs_grow_device(trans, device, old_size);
2063 btrfs_end_transaction(trans, dev_root);
2066 /* step two, relocate all the chunks */
2067 path = btrfs_alloc_path();
2070 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2071 key.offset = (u64)-1;
2072 key.type = BTRFS_CHUNK_ITEM_KEY;
2075 ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0);
2080 * this shouldn't happen, it means the last relocate
2086 ret = btrfs_previous_item(chunk_root, path, 0,
2087 BTRFS_CHUNK_ITEM_KEY);
2091 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2093 if (found_key.objectid != key.objectid)
2096 /* chunk zero is special */
2097 if (found_key.offset == 0)
2100 btrfs_release_path(path);
2101 ret = btrfs_relocate_chunk(chunk_root,
2102 chunk_root->root_key.objectid,
2105 BUG_ON(ret && ret != -ENOSPC);
2106 key.offset = found_key.offset - 1;
2110 btrfs_free_path(path);
2111 mutex_unlock(&dev_root->fs_info->volume_mutex);
2116 * shrinking a device means finding all of the device extents past
2117 * the new size, and then following the back refs to the chunks.
2118 * The chunk relocation code actually frees the device extent
2120 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size)
2122 struct btrfs_trans_handle *trans;
2123 struct btrfs_root *root = device->dev_root;
2124 struct btrfs_dev_extent *dev_extent = NULL;
2125 struct btrfs_path *path;
2133 bool retried = false;
2134 struct extent_buffer *l;
2135 struct btrfs_key key;
2136 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2137 u64 old_total = btrfs_super_total_bytes(super_copy);
2138 u64 old_size = device->total_bytes;
2139 u64 diff = device->total_bytes - new_size;
2141 if (new_size >= device->total_bytes)
2144 path = btrfs_alloc_path();
2152 device->total_bytes = new_size;
2153 if (device->writeable)
2154 device->fs_devices->total_rw_bytes -= diff;
2155 unlock_chunks(root);
2158 key.objectid = device->devid;
2159 key.offset = (u64)-1;
2160 key.type = BTRFS_DEV_EXTENT_KEY;
2163 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2167 ret = btrfs_previous_item(root, path, 0, key.type);
2172 btrfs_release_path(path);
2177 slot = path->slots[0];
2178 btrfs_item_key_to_cpu(l, &key, path->slots[0]);
2180 if (key.objectid != device->devid) {
2181 btrfs_release_path(path);
2185 dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent);
2186 length = btrfs_dev_extent_length(l, dev_extent);
2188 if (key.offset + length <= new_size) {
2189 btrfs_release_path(path);
2193 chunk_tree = btrfs_dev_extent_chunk_tree(l, dev_extent);
2194 chunk_objectid = btrfs_dev_extent_chunk_objectid(l, dev_extent);
2195 chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent);
2196 btrfs_release_path(path);
2198 ret = btrfs_relocate_chunk(root, chunk_tree, chunk_objectid,
2200 if (ret && ret != -ENOSPC)
2207 if (failed && !retried) {
2211 } else if (failed && retried) {
2215 device->total_bytes = old_size;
2216 if (device->writeable)
2217 device->fs_devices->total_rw_bytes += diff;
2218 unlock_chunks(root);
2222 /* Shrinking succeeded, else we would be at "done". */
2223 trans = btrfs_start_transaction(root, 0);
2224 if (IS_ERR(trans)) {
2225 ret = PTR_ERR(trans);
2231 device->disk_total_bytes = new_size;
2232 /* Now btrfs_update_device() will change the on-disk size. */
2233 ret = btrfs_update_device(trans, device);
2235 unlock_chunks(root);
2236 btrfs_end_transaction(trans, root);
2239 WARN_ON(diff > old_total);
2240 btrfs_set_super_total_bytes(super_copy, old_total - diff);
2241 unlock_chunks(root);
2242 btrfs_end_transaction(trans, root);
2244 btrfs_free_path(path);
2248 static int btrfs_add_system_chunk(struct btrfs_trans_handle *trans,
2249 struct btrfs_root *root,
2250 struct btrfs_key *key,
2251 struct btrfs_chunk *chunk, int item_size)
2253 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
2254 struct btrfs_disk_key disk_key;
2258 array_size = btrfs_super_sys_array_size(super_copy);
2259 if (array_size + item_size > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE)
2262 ptr = super_copy->sys_chunk_array + array_size;
2263 btrfs_cpu_key_to_disk(&disk_key, key);
2264 memcpy(ptr, &disk_key, sizeof(disk_key));
2265 ptr += sizeof(disk_key);
2266 memcpy(ptr, chunk, item_size);
2267 item_size += sizeof(disk_key);
2268 btrfs_set_super_sys_array_size(super_copy, array_size + item_size);
2273 * sort the devices in descending order by max_avail, total_avail
2275 static int btrfs_cmp_device_info(const void *a, const void *b)
2277 const struct btrfs_device_info *di_a = a;
2278 const struct btrfs_device_info *di_b = b;
2280 if (di_a->max_avail > di_b->max_avail)
2282 if (di_a->max_avail < di_b->max_avail)
2284 if (di_a->total_avail > di_b->total_avail)
2286 if (di_a->total_avail < di_b->total_avail)
2291 static int __btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2292 struct btrfs_root *extent_root,
2293 struct map_lookup **map_ret,
2294 u64 *num_bytes_out, u64 *stripe_size_out,
2295 u64 start, u64 type)
2297 struct btrfs_fs_info *info = extent_root->fs_info;
2298 struct btrfs_fs_devices *fs_devices = info->fs_devices;
2299 struct list_head *cur;
2300 struct map_lookup *map = NULL;
2301 struct extent_map_tree *em_tree;
2302 struct extent_map *em;
2303 struct btrfs_device_info *devices_info = NULL;
2305 int num_stripes; /* total number of stripes to allocate */
2306 int sub_stripes; /* sub_stripes info for map */
2307 int dev_stripes; /* stripes per dev */
2308 int devs_max; /* max devs to use */
2309 int devs_min; /* min devs needed */
2310 int devs_increment; /* ndevs has to be a multiple of this */
2311 int ncopies; /* how many copies to data has */
2313 u64 max_stripe_size;
2321 if ((type & BTRFS_BLOCK_GROUP_RAID1) &&
2322 (type & BTRFS_BLOCK_GROUP_DUP)) {
2324 type &= ~BTRFS_BLOCK_GROUP_DUP;
2327 if (list_empty(&fs_devices->alloc_list))
2334 devs_max = 0; /* 0 == as many as possible */
2338 * define the properties of each RAID type.
2339 * FIXME: move this to a global table and use it in all RAID
2342 if (type & (BTRFS_BLOCK_GROUP_DUP)) {
2346 } else if (type & (BTRFS_BLOCK_GROUP_RAID0)) {
2348 } else if (type & (BTRFS_BLOCK_GROUP_RAID1)) {
2353 } else if (type & (BTRFS_BLOCK_GROUP_RAID10)) {
2362 if (type & BTRFS_BLOCK_GROUP_DATA) {
2363 max_stripe_size = 1024 * 1024 * 1024;
2364 max_chunk_size = 10 * max_stripe_size;
2365 } else if (type & BTRFS_BLOCK_GROUP_METADATA) {
2366 max_stripe_size = 256 * 1024 * 1024;
2367 max_chunk_size = max_stripe_size;
2368 } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) {
2369 max_stripe_size = 8 * 1024 * 1024;
2370 max_chunk_size = 2 * max_stripe_size;
2372 printk(KERN_ERR "btrfs: invalid chunk type 0x%llx requested\n",
2377 /* we don't want a chunk larger than 10% of writeable space */
2378 max_chunk_size = min(div_factor(fs_devices->total_rw_bytes, 1),
2381 devices_info = kzalloc(sizeof(*devices_info) * fs_devices->rw_devices,
2386 cur = fs_devices->alloc_list.next;
2389 * in the first pass through the devices list, we gather information
2390 * about the available holes on each device.
2393 while (cur != &fs_devices->alloc_list) {
2394 struct btrfs_device *device;
2398 device = list_entry(cur, struct btrfs_device, dev_alloc_list);
2402 if (!device->writeable) {
2404 "btrfs: read-only device in alloc_list\n");
2409 if (!device->in_fs_metadata)
2412 if (device->total_bytes > device->bytes_used)
2413 total_avail = device->total_bytes - device->bytes_used;
2416 /* avail is off by max(alloc_start, 1MB), but that is the same
2417 * for all devices, so it doesn't hurt the sorting later on
2420 ret = find_free_dev_extent(trans, device,
2421 max_stripe_size * dev_stripes,
2422 &dev_offset, &max_avail);
2423 if (ret && ret != -ENOSPC)
2427 max_avail = max_stripe_size * dev_stripes;
2429 if (max_avail < BTRFS_STRIPE_LEN * dev_stripes)
2432 devices_info[ndevs].dev_offset = dev_offset;
2433 devices_info[ndevs].max_avail = max_avail;
2434 devices_info[ndevs].total_avail = total_avail;
2435 devices_info[ndevs].dev = device;
2440 * now sort the devices by hole size / available space
2442 sort(devices_info, ndevs, sizeof(struct btrfs_device_info),
2443 btrfs_cmp_device_info, NULL);
2445 /* round down to number of usable stripes */
2446 ndevs -= ndevs % devs_increment;
2448 if (ndevs < devs_increment * sub_stripes || ndevs < devs_min) {
2453 if (devs_max && ndevs > devs_max)
2456 * the primary goal is to maximize the number of stripes, so use as many
2457 * devices as possible, even if the stripes are not maximum sized.
2459 stripe_size = devices_info[ndevs-1].max_avail;
2460 num_stripes = ndevs * dev_stripes;
2462 if (stripe_size * num_stripes > max_chunk_size * ncopies) {
2463 stripe_size = max_chunk_size * ncopies;
2464 do_div(stripe_size, num_stripes);
2467 do_div(stripe_size, dev_stripes);
2468 do_div(stripe_size, BTRFS_STRIPE_LEN);
2469 stripe_size *= BTRFS_STRIPE_LEN;
2471 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
2476 map->num_stripes = num_stripes;
2478 for (i = 0; i < ndevs; ++i) {
2479 for (j = 0; j < dev_stripes; ++j) {
2480 int s = i * dev_stripes + j;
2481 map->stripes[s].dev = devices_info[i].dev;
2482 map->stripes[s].physical = devices_info[i].dev_offset +
2486 map->sector_size = extent_root->sectorsize;
2487 map->stripe_len = BTRFS_STRIPE_LEN;
2488 map->io_align = BTRFS_STRIPE_LEN;
2489 map->io_width = BTRFS_STRIPE_LEN;
2491 map->sub_stripes = sub_stripes;
2494 num_bytes = stripe_size * (num_stripes / ncopies);
2496 *stripe_size_out = stripe_size;
2497 *num_bytes_out = num_bytes;
2499 trace_btrfs_chunk_alloc(info->chunk_root, map, start, num_bytes);
2501 em = alloc_extent_map();
2506 em->bdev = (struct block_device *)map;
2508 em->len = num_bytes;
2509 em->block_start = 0;
2510 em->block_len = em->len;
2512 em_tree = &extent_root->fs_info->mapping_tree.map_tree;
2513 write_lock(&em_tree->lock);
2514 ret = add_extent_mapping(em_tree, em);
2515 write_unlock(&em_tree->lock);
2517 free_extent_map(em);
2519 ret = btrfs_make_block_group(trans, extent_root, 0, type,
2520 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2524 for (i = 0; i < map->num_stripes; ++i) {
2525 struct btrfs_device *device;
2528 device = map->stripes[i].dev;
2529 dev_offset = map->stripes[i].physical;
2531 ret = btrfs_alloc_dev_extent(trans, device,
2532 info->chunk_root->root_key.objectid,
2533 BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2534 start, dev_offset, stripe_size);
2538 kfree(devices_info);
2543 kfree(devices_info);
2547 static int __finish_chunk_alloc(struct btrfs_trans_handle *trans,
2548 struct btrfs_root *extent_root,
2549 struct map_lookup *map, u64 chunk_offset,
2550 u64 chunk_size, u64 stripe_size)
2553 struct btrfs_key key;
2554 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2555 struct btrfs_device *device;
2556 struct btrfs_chunk *chunk;
2557 struct btrfs_stripe *stripe;
2558 size_t item_size = btrfs_chunk_item_size(map->num_stripes);
2562 chunk = kzalloc(item_size, GFP_NOFS);
2567 while (index < map->num_stripes) {
2568 device = map->stripes[index].dev;
2569 device->bytes_used += stripe_size;
2570 ret = btrfs_update_device(trans, device);
2576 stripe = &chunk->stripe;
2577 while (index < map->num_stripes) {
2578 device = map->stripes[index].dev;
2579 dev_offset = map->stripes[index].physical;
2581 btrfs_set_stack_stripe_devid(stripe, device->devid);
2582 btrfs_set_stack_stripe_offset(stripe, dev_offset);
2583 memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE);
2588 btrfs_set_stack_chunk_length(chunk, chunk_size);
2589 btrfs_set_stack_chunk_owner(chunk, extent_root->root_key.objectid);
2590 btrfs_set_stack_chunk_stripe_len(chunk, map->stripe_len);
2591 btrfs_set_stack_chunk_type(chunk, map->type);
2592 btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes);
2593 btrfs_set_stack_chunk_io_align(chunk, map->stripe_len);
2594 btrfs_set_stack_chunk_io_width(chunk, map->stripe_len);
2595 btrfs_set_stack_chunk_sector_size(chunk, extent_root->sectorsize);
2596 btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes);
2598 key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
2599 key.type = BTRFS_CHUNK_ITEM_KEY;
2600 key.offset = chunk_offset;
2602 ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size);
2605 if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) {
2606 ret = btrfs_add_system_chunk(trans, chunk_root, &key, chunk,
2616 * Chunk allocation falls into two parts. The first part does works
2617 * that make the new allocated chunk useable, but not do any operation
2618 * that modifies the chunk tree. The second part does the works that
2619 * require modifying the chunk tree. This division is important for the
2620 * bootstrap process of adding storage to a seed btrfs.
2622 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
2623 struct btrfs_root *extent_root, u64 type)
2628 struct map_lookup *map;
2629 struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
2632 ret = find_next_chunk(chunk_root, BTRFS_FIRST_CHUNK_TREE_OBJECTID,
2637 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2638 &stripe_size, chunk_offset, type);
2642 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2643 chunk_size, stripe_size);
2648 static noinline int init_first_rw_device(struct btrfs_trans_handle *trans,
2649 struct btrfs_root *root,
2650 struct btrfs_device *device)
2653 u64 sys_chunk_offset;
2657 u64 sys_stripe_size;
2659 struct map_lookup *map;
2660 struct map_lookup *sys_map;
2661 struct btrfs_fs_info *fs_info = root->fs_info;
2662 struct btrfs_root *extent_root = fs_info->extent_root;
2665 ret = find_next_chunk(fs_info->chunk_root,
2666 BTRFS_FIRST_CHUNK_TREE_OBJECTID, &chunk_offset);
2669 alloc_profile = BTRFS_BLOCK_GROUP_METADATA |
2670 (fs_info->metadata_alloc_profile &
2671 fs_info->avail_metadata_alloc_bits);
2672 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2674 ret = __btrfs_alloc_chunk(trans, extent_root, &map, &chunk_size,
2675 &stripe_size, chunk_offset, alloc_profile);
2678 sys_chunk_offset = chunk_offset + chunk_size;
2680 alloc_profile = BTRFS_BLOCK_GROUP_SYSTEM |
2681 (fs_info->system_alloc_profile &
2682 fs_info->avail_system_alloc_bits);
2683 alloc_profile = btrfs_reduce_alloc_profile(root, alloc_profile);
2685 ret = __btrfs_alloc_chunk(trans, extent_root, &sys_map,
2686 &sys_chunk_size, &sys_stripe_size,
2687 sys_chunk_offset, alloc_profile);
2690 ret = btrfs_add_device(trans, fs_info->chunk_root, device);
2694 * Modifying chunk tree needs allocating new blocks from both
2695 * system block group and metadata block group. So we only can
2696 * do operations require modifying the chunk tree after both
2697 * block groups were created.
2699 ret = __finish_chunk_alloc(trans, extent_root, map, chunk_offset,
2700 chunk_size, stripe_size);
2703 ret = __finish_chunk_alloc(trans, extent_root, sys_map,
2704 sys_chunk_offset, sys_chunk_size,
2710 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset)
2712 struct extent_map *em;
2713 struct map_lookup *map;
2714 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
2718 read_lock(&map_tree->map_tree.lock);
2719 em = lookup_extent_mapping(&map_tree->map_tree, chunk_offset, 1);
2720 read_unlock(&map_tree->map_tree.lock);
2724 if (btrfs_test_opt(root, DEGRADED)) {
2725 free_extent_map(em);
2729 map = (struct map_lookup *)em->bdev;
2730 for (i = 0; i < map->num_stripes; i++) {
2731 if (!map->stripes[i].dev->writeable) {
2736 free_extent_map(em);
2740 void btrfs_mapping_init(struct btrfs_mapping_tree *tree)
2742 extent_map_tree_init(&tree->map_tree);
2745 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree)
2747 struct extent_map *em;
2750 write_lock(&tree->map_tree.lock);
2751 em = lookup_extent_mapping(&tree->map_tree, 0, (u64)-1);
2753 remove_extent_mapping(&tree->map_tree, em);
2754 write_unlock(&tree->map_tree.lock);
2759 free_extent_map(em);
2760 /* once for the tree */
2761 free_extent_map(em);
2765 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len)
2767 struct extent_map *em;
2768 struct map_lookup *map;
2769 struct extent_map_tree *em_tree = &map_tree->map_tree;
2772 read_lock(&em_tree->lock);
2773 em = lookup_extent_mapping(em_tree, logical, len);
2774 read_unlock(&em_tree->lock);
2777 BUG_ON(em->start > logical || em->start + em->len < logical);
2778 map = (struct map_lookup *)em->bdev;
2779 if (map->type & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1))
2780 ret = map->num_stripes;
2781 else if (map->type & BTRFS_BLOCK_GROUP_RAID10)
2782 ret = map->sub_stripes;
2785 free_extent_map(em);
2789 static int find_live_mirror(struct map_lookup *map, int first, int num,
2793 if (map->stripes[optimal].dev->bdev)
2795 for (i = first; i < first + num; i++) {
2796 if (map->stripes[i].dev->bdev)
2799 /* we couldn't find one that doesn't fail. Just return something
2800 * and the io error handling code will clean up eventually
2805 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
2806 u64 logical, u64 *length,
2807 struct btrfs_multi_bio **multi_ret,
2810 struct extent_map *em;
2811 struct map_lookup *map;
2812 struct extent_map_tree *em_tree = &map_tree->map_tree;
2815 u64 stripe_end_offset;
2819 int stripes_allocated = 8;
2820 int stripes_required = 1;
2825 struct btrfs_multi_bio *multi = NULL;
2827 if (multi_ret && !(rw & (REQ_WRITE | REQ_DISCARD)))
2828 stripes_allocated = 1;
2831 multi = kzalloc(btrfs_multi_bio_size(stripes_allocated),
2836 atomic_set(&multi->error, 0);
2839 read_lock(&em_tree->lock);
2840 em = lookup_extent_mapping(em_tree, logical, *length);
2841 read_unlock(&em_tree->lock);
2844 printk(KERN_CRIT "unable to find logical %llu len %llu\n",
2845 (unsigned long long)logical,
2846 (unsigned long long)*length);
2850 BUG_ON(em->start > logical || em->start + em->len < logical);
2851 map = (struct map_lookup *)em->bdev;
2852 offset = logical - em->start;
2854 if (mirror_num > map->num_stripes)
2857 /* if our multi bio struct is too small, back off and try again */
2858 if (rw & REQ_WRITE) {
2859 if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
2860 BTRFS_BLOCK_GROUP_DUP)) {
2861 stripes_required = map->num_stripes;
2863 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2864 stripes_required = map->sub_stripes;
2868 if (rw & REQ_DISCARD) {
2869 if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2870 BTRFS_BLOCK_GROUP_RAID1 |
2871 BTRFS_BLOCK_GROUP_DUP |
2872 BTRFS_BLOCK_GROUP_RAID10)) {
2873 stripes_required = map->num_stripes;
2876 if (multi_ret && (rw & (REQ_WRITE | REQ_DISCARD)) &&
2877 stripes_allocated < stripes_required) {
2878 stripes_allocated = map->num_stripes;
2879 free_extent_map(em);
2885 * stripe_nr counts the total number of stripes we have to stride
2886 * to get to this block
2888 do_div(stripe_nr, map->stripe_len);
2890 stripe_offset = stripe_nr * map->stripe_len;
2891 BUG_ON(offset < stripe_offset);
2893 /* stripe_offset is the offset of this block in its stripe*/
2894 stripe_offset = offset - stripe_offset;
2896 if (rw & REQ_DISCARD)
2897 *length = min_t(u64, em->len - offset, *length);
2898 else if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
2899 BTRFS_BLOCK_GROUP_RAID1 |
2900 BTRFS_BLOCK_GROUP_RAID10 |
2901 BTRFS_BLOCK_GROUP_DUP)) {
2902 /* we limit the length of each bio to what fits in a stripe */
2903 *length = min_t(u64, em->len - offset,
2904 map->stripe_len - stripe_offset);
2906 *length = em->len - offset;
2914 stripe_nr_orig = stripe_nr;
2915 stripe_nr_end = (offset + *length + map->stripe_len - 1) &
2916 (~(map->stripe_len - 1));
2917 do_div(stripe_nr_end, map->stripe_len);
2918 stripe_end_offset = stripe_nr_end * map->stripe_len -
2920 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2921 if (rw & REQ_DISCARD)
2922 num_stripes = min_t(u64, map->num_stripes,
2923 stripe_nr_end - stripe_nr_orig);
2924 stripe_index = do_div(stripe_nr, map->num_stripes);
2925 } else if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
2926 if (rw & (REQ_WRITE | REQ_DISCARD))
2927 num_stripes = map->num_stripes;
2928 else if (mirror_num)
2929 stripe_index = mirror_num - 1;
2931 stripe_index = find_live_mirror(map, 0,
2933 current->pid % map->num_stripes);
2936 } else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
2937 if (rw & (REQ_WRITE | REQ_DISCARD))
2938 num_stripes = map->num_stripes;
2939 else if (mirror_num)
2940 stripe_index = mirror_num - 1;
2942 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
2943 int factor = map->num_stripes / map->sub_stripes;
2945 stripe_index = do_div(stripe_nr, factor);
2946 stripe_index *= map->sub_stripes;
2949 num_stripes = map->sub_stripes;
2950 else if (rw & REQ_DISCARD)
2951 num_stripes = min_t(u64, map->sub_stripes *
2952 (stripe_nr_end - stripe_nr_orig),
2954 else if (mirror_num)
2955 stripe_index += mirror_num - 1;
2957 stripe_index = find_live_mirror(map, stripe_index,
2958 map->sub_stripes, stripe_index +
2959 current->pid % map->sub_stripes);
2963 * after this do_div call, stripe_nr is the number of stripes
2964 * on this device we have to walk to find the data, and
2965 * stripe_index is the number of our device in the stripe array
2967 stripe_index = do_div(stripe_nr, map->num_stripes);
2969 BUG_ON(stripe_index >= map->num_stripes);
2971 if (rw & REQ_DISCARD) {
2972 for (i = 0; i < num_stripes; i++) {
2973 multi->stripes[i].physical =
2974 map->stripes[stripe_index].physical +
2975 stripe_offset + stripe_nr * map->stripe_len;
2976 multi->stripes[i].dev = map->stripes[stripe_index].dev;
2978 if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
2980 u32 last_stripe = 0;
2983 div_u64_rem(stripe_nr_end - 1,
2987 for (j = 0; j < map->num_stripes; j++) {
2990 div_u64_rem(stripe_nr_end - 1 - j,
2991 map->num_stripes, &test);
2992 if (test == stripe_index)
2995 stripes = stripe_nr_end - 1 - j;
2996 do_div(stripes, map->num_stripes);
2997 multi->stripes[i].length = map->stripe_len *
2998 (stripes - stripe_nr + 1);
3001 multi->stripes[i].length -=
3005 if (stripe_index == last_stripe)
3006 multi->stripes[i].length -=
3008 } else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3011 int factor = map->num_stripes /
3013 u32 last_stripe = 0;
3015 div_u64_rem(stripe_nr_end - 1,
3016 factor, &last_stripe);
3017 last_stripe *= map->sub_stripes;
3019 for (j = 0; j < factor; j++) {
3022 div_u64_rem(stripe_nr_end - 1 - j,
3026 stripe_index / map->sub_stripes)
3029 stripes = stripe_nr_end - 1 - j;
3030 do_div(stripes, factor);
3031 multi->stripes[i].length = map->stripe_len *
3032 (stripes - stripe_nr + 1);
3034 if (i < map->sub_stripes) {
3035 multi->stripes[i].length -=
3037 if (i == map->sub_stripes - 1)
3040 if (stripe_index >= last_stripe &&
3041 stripe_index <= (last_stripe +
3042 map->sub_stripes - 1)) {
3043 multi->stripes[i].length -=
3047 multi->stripes[i].length = *length;
3050 if (stripe_index == map->num_stripes) {
3051 /* This could only happen for RAID0/10 */
3057 for (i = 0; i < num_stripes; i++) {
3058 multi->stripes[i].physical =
3059 map->stripes[stripe_index].physical +
3061 stripe_nr * map->stripe_len;
3062 multi->stripes[i].dev =
3063 map->stripes[stripe_index].dev;
3069 multi->num_stripes = num_stripes;
3070 multi->max_errors = max_errors;
3073 free_extent_map(em);
3077 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
3078 u64 logical, u64 *length,
3079 struct btrfs_multi_bio **multi_ret, int mirror_num)
3081 return __btrfs_map_block(map_tree, rw, logical, length, multi_ret,
3085 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
3086 u64 chunk_start, u64 physical, u64 devid,
3087 u64 **logical, int *naddrs, int *stripe_len)
3089 struct extent_map_tree *em_tree = &map_tree->map_tree;
3090 struct extent_map *em;
3091 struct map_lookup *map;
3098 read_lock(&em_tree->lock);
3099 em = lookup_extent_mapping(em_tree, chunk_start, 1);
3100 read_unlock(&em_tree->lock);
3102 BUG_ON(!em || em->start != chunk_start);
3103 map = (struct map_lookup *)em->bdev;
3106 if (map->type & BTRFS_BLOCK_GROUP_RAID10)
3107 do_div(length, map->num_stripes / map->sub_stripes);
3108 else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
3109 do_div(length, map->num_stripes);
3111 buf = kzalloc(sizeof(u64) * map->num_stripes, GFP_NOFS);
3114 for (i = 0; i < map->num_stripes; i++) {
3115 if (devid && map->stripes[i].dev->devid != devid)
3117 if (map->stripes[i].physical > physical ||
3118 map->stripes[i].physical + length <= physical)
3121 stripe_nr = physical - map->stripes[i].physical;
3122 do_div(stripe_nr, map->stripe_len);
3124 if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
3125 stripe_nr = stripe_nr * map->num_stripes + i;
3126 do_div(stripe_nr, map->sub_stripes);
3127 } else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
3128 stripe_nr = stripe_nr * map->num_stripes + i;
3130 bytenr = chunk_start + stripe_nr * map->stripe_len;
3131 WARN_ON(nr >= map->num_stripes);
3132 for (j = 0; j < nr; j++) {
3133 if (buf[j] == bytenr)
3137 WARN_ON(nr >= map->num_stripes);
3144 *stripe_len = map->stripe_len;
3146 free_extent_map(em);
3150 static void end_bio_multi_stripe(struct bio *bio, int err)
3152 struct btrfs_multi_bio *multi = bio->bi_private;
3153 int is_orig_bio = 0;
3156 atomic_inc(&multi->error);
3158 if (bio == multi->orig_bio)
3161 if (atomic_dec_and_test(&multi->stripes_pending)) {
3164 bio = multi->orig_bio;
3166 bio->bi_private = multi->private;
3167 bio->bi_end_io = multi->end_io;
3168 /* only send an error to the higher layers if it is
3169 * beyond the tolerance of the multi-bio
3171 if (atomic_read(&multi->error) > multi->max_errors) {
3175 * this bio is actually up to date, we didn't
3176 * go over the max number of errors
3178 set_bit(BIO_UPTODATE, &bio->bi_flags);
3183 bio_endio(bio, err);
3184 } else if (!is_orig_bio) {
3189 struct async_sched {
3192 struct btrfs_fs_info *info;
3193 struct btrfs_work work;
3197 * see run_scheduled_bios for a description of why bios are collected for
3200 * This will add one bio to the pending list for a device and make sure
3201 * the work struct is scheduled.
3203 static noinline int schedule_bio(struct btrfs_root *root,
3204 struct btrfs_device *device,
3205 int rw, struct bio *bio)
3207 int should_queue = 1;
3208 struct btrfs_pending_bios *pending_bios;
3210 /* don't bother with additional async steps for reads, right now */
3211 if (!(rw & REQ_WRITE)) {
3213 submit_bio(rw, bio);
3219 * nr_async_bios allows us to reliably return congestion to the
3220 * higher layers. Otherwise, the async bio makes it appear we have
3221 * made progress against dirty pages when we've really just put it
3222 * on a queue for later
3224 atomic_inc(&root->fs_info->nr_async_bios);
3225 WARN_ON(bio->bi_next);
3226 bio->bi_next = NULL;
3229 spin_lock(&device->io_lock);
3230 if (bio->bi_rw & REQ_SYNC)
3231 pending_bios = &device->pending_sync_bios;
3233 pending_bios = &device->pending_bios;
3235 if (pending_bios->tail)
3236 pending_bios->tail->bi_next = bio;
3238 pending_bios->tail = bio;
3239 if (!pending_bios->head)
3240 pending_bios->head = bio;
3241 if (device->running_pending)
3244 spin_unlock(&device->io_lock);
3247 btrfs_queue_worker(&root->fs_info->submit_workers,
3252 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
3253 int mirror_num, int async_submit)
3255 struct btrfs_mapping_tree *map_tree;
3256 struct btrfs_device *dev;
3257 struct bio *first_bio = bio;
3258 u64 logical = (u64)bio->bi_sector << 9;
3261 struct btrfs_multi_bio *multi = NULL;
3266 length = bio->bi_size;
3267 map_tree = &root->fs_info->mapping_tree;
3268 map_length = length;
3270 ret = btrfs_map_block(map_tree, rw, logical, &map_length, &multi,
3274 total_devs = multi->num_stripes;
3275 if (map_length < length) {
3276 printk(KERN_CRIT "mapping failed logical %llu bio len %llu "
3277 "len %llu\n", (unsigned long long)logical,
3278 (unsigned long long)length,
3279 (unsigned long long)map_length);
3282 multi->end_io = first_bio->bi_end_io;
3283 multi->private = first_bio->bi_private;
3284 multi->orig_bio = first_bio;
3285 atomic_set(&multi->stripes_pending, multi->num_stripes);
3287 while (dev_nr < total_devs) {
3288 if (total_devs > 1) {
3289 if (dev_nr < total_devs - 1) {
3290 bio = bio_clone(first_bio, GFP_NOFS);
3295 bio->bi_private = multi;
3296 bio->bi_end_io = end_bio_multi_stripe;
3298 bio->bi_sector = multi->stripes[dev_nr].physical >> 9;
3299 dev = multi->stripes[dev_nr].dev;
3300 if (dev && dev->bdev && (rw != WRITE || dev->writeable)) {
3301 bio->bi_bdev = dev->bdev;
3303 schedule_bio(root, dev, rw, bio);
3305 submit_bio(rw, bio);
3307 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
3308 bio->bi_sector = logical >> 9;
3309 bio_endio(bio, -EIO);
3313 if (total_devs == 1)
3318 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
3321 struct btrfs_device *device;
3322 struct btrfs_fs_devices *cur_devices;
3324 cur_devices = root->fs_info->fs_devices;
3325 while (cur_devices) {
3327 !memcmp(cur_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3328 device = __find_device(&cur_devices->devices,
3333 cur_devices = cur_devices->seed;
3338 static struct btrfs_device *add_missing_dev(struct btrfs_root *root,
3339 u64 devid, u8 *dev_uuid)
3341 struct btrfs_device *device;
3342 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
3344 device = kzalloc(sizeof(*device), GFP_NOFS);
3347 list_add(&device->dev_list,
3348 &fs_devices->devices);
3349 device->dev_root = root->fs_info->dev_root;
3350 device->devid = devid;
3351 device->work.func = pending_bios_fn;
3352 device->fs_devices = fs_devices;
3353 device->missing = 1;
3354 fs_devices->num_devices++;
3355 fs_devices->missing_devices++;
3356 spin_lock_init(&device->io_lock);
3357 INIT_LIST_HEAD(&device->dev_alloc_list);
3358 memcpy(device->uuid, dev_uuid, BTRFS_UUID_SIZE);
3362 static int read_one_chunk(struct btrfs_root *root, struct btrfs_key *key,
3363 struct extent_buffer *leaf,
3364 struct btrfs_chunk *chunk)
3366 struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
3367 struct map_lookup *map;
3368 struct extent_map *em;
3372 u8 uuid[BTRFS_UUID_SIZE];
3377 logical = key->offset;
3378 length = btrfs_chunk_length(leaf, chunk);
3380 read_lock(&map_tree->map_tree.lock);
3381 em = lookup_extent_mapping(&map_tree->map_tree, logical, 1);
3382 read_unlock(&map_tree->map_tree.lock);
3384 /* already mapped? */
3385 if (em && em->start <= logical && em->start + em->len > logical) {
3386 free_extent_map(em);
3389 free_extent_map(em);
3392 em = alloc_extent_map();
3395 num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
3396 map = kmalloc(map_lookup_size(num_stripes), GFP_NOFS);
3398 free_extent_map(em);
3402 em->bdev = (struct block_device *)map;
3403 em->start = logical;
3405 em->block_start = 0;
3406 em->block_len = em->len;
3408 map->num_stripes = num_stripes;
3409 map->io_width = btrfs_chunk_io_width(leaf, chunk);
3410 map->io_align = btrfs_chunk_io_align(leaf, chunk);
3411 map->sector_size = btrfs_chunk_sector_size(leaf, chunk);
3412 map->stripe_len = btrfs_chunk_stripe_len(leaf, chunk);
3413 map->type = btrfs_chunk_type(leaf, chunk);
3414 map->sub_stripes = btrfs_chunk_sub_stripes(leaf, chunk);
3415 for (i = 0; i < num_stripes; i++) {
3416 map->stripes[i].physical =
3417 btrfs_stripe_offset_nr(leaf, chunk, i);
3418 devid = btrfs_stripe_devid_nr(leaf, chunk, i);
3419 read_extent_buffer(leaf, uuid, (unsigned long)
3420 btrfs_stripe_dev_uuid_nr(chunk, i),
3422 map->stripes[i].dev = btrfs_find_device(root, devid, uuid,
3424 if (!map->stripes[i].dev && !btrfs_test_opt(root, DEGRADED)) {
3426 free_extent_map(em);
3429 if (!map->stripes[i].dev) {
3430 map->stripes[i].dev =
3431 add_missing_dev(root, devid, uuid);
3432 if (!map->stripes[i].dev) {
3434 free_extent_map(em);
3438 map->stripes[i].dev->in_fs_metadata = 1;
3441 write_lock(&map_tree->map_tree.lock);
3442 ret = add_extent_mapping(&map_tree->map_tree, em);
3443 write_unlock(&map_tree->map_tree.lock);
3445 free_extent_map(em);
3450 static int fill_device_from_item(struct extent_buffer *leaf,
3451 struct btrfs_dev_item *dev_item,
3452 struct btrfs_device *device)
3456 device->devid = btrfs_device_id(leaf, dev_item);
3457 device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item);
3458 device->total_bytes = device->disk_total_bytes;
3459 device->bytes_used = btrfs_device_bytes_used(leaf, dev_item);
3460 device->type = btrfs_device_type(leaf, dev_item);
3461 device->io_align = btrfs_device_io_align(leaf, dev_item);
3462 device->io_width = btrfs_device_io_width(leaf, dev_item);
3463 device->sector_size = btrfs_device_sector_size(leaf, dev_item);
3465 ptr = (unsigned long)btrfs_device_uuid(dev_item);
3466 read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
3471 static int open_seed_devices(struct btrfs_root *root, u8 *fsid)
3473 struct btrfs_fs_devices *fs_devices;
3476 mutex_lock(&uuid_mutex);
3478 fs_devices = root->fs_info->fs_devices->seed;
3479 while (fs_devices) {
3480 if (!memcmp(fs_devices->fsid, fsid, BTRFS_UUID_SIZE)) {
3484 fs_devices = fs_devices->seed;
3487 fs_devices = find_fsid(fsid);
3493 fs_devices = clone_fs_devices(fs_devices);
3494 if (IS_ERR(fs_devices)) {
3495 ret = PTR_ERR(fs_devices);
3499 ret = __btrfs_open_devices(fs_devices, FMODE_READ,
3500 root->fs_info->bdev_holder);
3504 if (!fs_devices->seeding) {
3505 __btrfs_close_devices(fs_devices);
3506 free_fs_devices(fs_devices);
3511 fs_devices->seed = root->fs_info->fs_devices->seed;
3512 root->fs_info->fs_devices->seed = fs_devices;
3514 mutex_unlock(&uuid_mutex);
3518 static int read_one_dev(struct btrfs_root *root,
3519 struct extent_buffer *leaf,
3520 struct btrfs_dev_item *dev_item)
3522 struct btrfs_device *device;
3525 u8 fs_uuid[BTRFS_UUID_SIZE];
3526 u8 dev_uuid[BTRFS_UUID_SIZE];
3528 devid = btrfs_device_id(leaf, dev_item);
3529 read_extent_buffer(leaf, dev_uuid,
3530 (unsigned long)btrfs_device_uuid(dev_item),
3532 read_extent_buffer(leaf, fs_uuid,
3533 (unsigned long)btrfs_device_fsid(dev_item),
3536 if (memcmp(fs_uuid, root->fs_info->fsid, BTRFS_UUID_SIZE)) {
3537 ret = open_seed_devices(root, fs_uuid);
3538 if (ret && !btrfs_test_opt(root, DEGRADED))
3542 device = btrfs_find_device(root, devid, dev_uuid, fs_uuid);
3543 if (!device || !device->bdev) {
3544 if (!btrfs_test_opt(root, DEGRADED))
3548 printk(KERN_WARNING "warning devid %llu missing\n",
3549 (unsigned long long)devid);
3550 device = add_missing_dev(root, devid, dev_uuid);
3553 } else if (!device->missing) {
3555 * this happens when a device that was properly setup
3556 * in the device info lists suddenly goes bad.
3557 * device->bdev is NULL, and so we have to set
3558 * device->missing to one here
3560 root->fs_info->fs_devices->missing_devices++;
3561 device->missing = 1;
3565 if (device->fs_devices != root->fs_info->fs_devices) {
3566 BUG_ON(device->writeable);
3567 if (device->generation !=
3568 btrfs_device_generation(leaf, dev_item))
3572 fill_device_from_item(leaf, dev_item, device);
3573 device->dev_root = root->fs_info->dev_root;
3574 device->in_fs_metadata = 1;
3575 if (device->writeable)
3576 device->fs_devices->total_rw_bytes += device->total_bytes;
3581 int btrfs_read_sys_array(struct btrfs_root *root)
3583 struct btrfs_super_block *super_copy = &root->fs_info->super_copy;
3584 struct extent_buffer *sb;
3585 struct btrfs_disk_key *disk_key;
3586 struct btrfs_chunk *chunk;
3588 unsigned long sb_ptr;
3594 struct btrfs_key key;
3596 sb = btrfs_find_create_tree_block(root, BTRFS_SUPER_INFO_OFFSET,
3597 BTRFS_SUPER_INFO_SIZE);
3600 btrfs_set_buffer_uptodate(sb);
3601 btrfs_set_buffer_lockdep_class(sb, 0);
3603 write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
3604 array_size = btrfs_super_sys_array_size(super_copy);
3606 ptr = super_copy->sys_chunk_array;
3607 sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
3610 while (cur < array_size) {
3611 disk_key = (struct btrfs_disk_key *)ptr;
3612 btrfs_disk_key_to_cpu(&key, disk_key);
3614 len = sizeof(*disk_key); ptr += len;
3618 if (key.type == BTRFS_CHUNK_ITEM_KEY) {
3619 chunk = (struct btrfs_chunk *)sb_ptr;
3620 ret = read_one_chunk(root, &key, sb, chunk);
3623 num_stripes = btrfs_chunk_num_stripes(sb, chunk);
3624 len = btrfs_chunk_item_size(num_stripes);
3633 free_extent_buffer(sb);
3637 int btrfs_read_chunk_tree(struct btrfs_root *root)
3639 struct btrfs_path *path;
3640 struct extent_buffer *leaf;
3641 struct btrfs_key key;
3642 struct btrfs_key found_key;
3646 root = root->fs_info->chunk_root;
3648 path = btrfs_alloc_path();
3652 /* first we search for all of the device items, and then we
3653 * read in all of the chunk items. This way we can create chunk
3654 * mappings that reference all of the devices that are afound
3656 key.objectid = BTRFS_DEV_ITEMS_OBJECTID;
3660 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3664 leaf = path->nodes[0];
3665 slot = path->slots[0];
3666 if (slot >= btrfs_header_nritems(leaf)) {
3667 ret = btrfs_next_leaf(root, path);
3674 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3675 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3676 if (found_key.objectid != BTRFS_DEV_ITEMS_OBJECTID)
3678 if (found_key.type == BTRFS_DEV_ITEM_KEY) {
3679 struct btrfs_dev_item *dev_item;
3680 dev_item = btrfs_item_ptr(leaf, slot,
3681 struct btrfs_dev_item);
3682 ret = read_one_dev(root, leaf, dev_item);
3686 } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) {
3687 struct btrfs_chunk *chunk;
3688 chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk);
3689 ret = read_one_chunk(root, &found_key, leaf, chunk);
3695 if (key.objectid == BTRFS_DEV_ITEMS_OBJECTID) {
3697 btrfs_release_path(path);
3702 btrfs_free_path(path);